How to Baby Your Engine Cooling System

Engine Cooling System

Don’t let your engine cooling system be the reason your truck has a problem!  Engine cooling systems protect engines and keep them working at the most efficient temperature. Use these quick and easy tips during your day to keep engines running cool.

Coolant (antifreeze) helps protect the engine from rust, corrosion and overheating. Just like the rest of your truck, heat negatively affects the engine cooling system. It is important to keep your cooling system in good working condition. Luckily, engine cooling system issues are easy to spot, fix and prevent.

Engine Cooling System Overview

The engine cooling system includes the radiator, radiator cap, water pump and fan, as well as the thermostat and hoses that connect the radiator to the engine. The water pump moves the coolant from the bottom of the radiator to the engine. Then the coolant circulates through the internal water jackets. The coolant removes the extra heat from the engine. The hot coolant is then pumped through the thermostat and radiator hose to the reservoir and pushed slowly through the radiator core. The heat is emitted from the water and the coolant reaches the opposite side of the radiator and is transferred back to the engine through the water pump. From here, the process starts again.

The engine fan ensures the correct flow of air through the radiator while the truck is idling or moving slowly. Without the fan, the radiator would not be able to handle heat transfer if the truck is idling or moving slowly.

The thermostat keeps the engine cooling system at a specific temperature. It restricts the flow of coolant through the system until it has reached the appropriate level. Then the thermostat opens and allows the coolant to circulate through the radiator.

Water pumps are generally pretty durable, as they are very simple devices. The most common problems associated with them involve a leak in the seal or a bad bearing. Easily spot seal leaks which are generally close to the base. Bad bearing become noisy when something is wrong with them.


The Perfect Coolant Ratio

A 50/50 antifreeze/coolant to water ratio is recommended for optimal performance. An unequal antifreeze/coolant to water ratio can cause an inefficient exchange of heat. This puts extra stress on the engine cooling system, causing it to fail prematurely. This can also have a negative effect on the other fluids under the hood, including the engine oil, power steering and transmission fluids.

Measure the coolant to water ratio in a number of ways. The three most common are a hydrometer, a handheld refractometer or test strips. It is important that the coolant is accurately diluted with good quality water. Do not use hard water because it increases scaling on metal engine components. Use deionized or distilled water.


Common Engine Cooling System Issues

There are three common indicators of engine cooling system issues, coolant leaks, engine overheating, and slow warmup time. Use our service department’s guide and catch your truck’s cooling system issues and repair them before breaking down on the side of the road.

1. Coolant Leaks

Coolant leaks can be both internal and external. When there is an external leak, puddles or stains will start appearing on the driveway. This makes them easy to diagnose. External leaks generally stem from one of these areas: radiator hose, hose connection, water pump shaft, heater core, or radiator core.  On the other hand, internal leaks generally occur when coolant seeps into other parts of the engine. Internal leaks are a little more difficult to spot than external leaks. Frequently having to add coolant or having white exhaust smoke are signs of an internal leak and should be address as soon as possible. Internal leaks are very harmful to the engine.

2. Engine Overheating

Engines overheat for many reasons, however, the engine cooling system causes only a few. Here are a few examples of how the engine cooling system could cause an overheated engine.

Check for rust or other debris lodged in the different components of the cooling system. This would prevent coolant from properly circulating. To check your coolant for debris, wipe your finger around the neck of the radiator cap. If there is any grease, dirt or debris then it may be time for a radiator flush.

A high pitch squeal when the engine is running is a sign of a loose or slipping drive belt. If the belt is slipping it will not be able to turn the water pump fast enough to keep up with the engine’s cooling needs.

A defective or stuck thermostat blocks coolant from flowing to the engine. This causes the engine to overheat without the radiator getting warm. The only solution is to replace the thermostat.

A defective water pump won’t allow enough coolant to flow and bearing failure is often to blame. One of the first signs of bearing failure is a noisy water pump. If there is any movement of grinding sounds when moving the fan, replace the bearings.

3. Slow Warmup Time

The most likely cause of a slow warmup time is the thermostat. If the thermostat is stuck open, coolant will continue to circulate to the radiator even when the engine is cold. This means that the engine must run longer in order to warm up, which will be an issue when winter rolls around. To test if the thermostat is stuck open, squeeze the upper radiator hose (without hitting the fan) and see if coolant is flowing through it. If there is, the thermostat is either stuck open or missing all together.

So Stay Cool

Keep your truck running smoothing by making sure the engine cooling system is issue-free and ready for the summer heat! Our service department can help maintain your engine cooling system and help with any of your truck maintenance needs!


Kirk Booth is the Service Manager of Truck-N-Trailer, a family owned and operated shop dedicated to providing the best medium and light duty delivery and work trucks, vans, and services to fit the individual needs of its customers. He provides excellent service to his customers for over 13 years. Kirk has 25 years in the automotive industry and his technicians (and himself) hold many factory training certifications.  They take pride in being a “One Stop Shop.”